Yamaha CS 20M Service Manual

Page 1

CONTENTS

CODING GUIDE ............................................ 2

DISASSEMBLY PROCEDURE ................................. 3

SPECIFICATIONS .......................................... 4

PANEL LAYOUT ........................................... 5
SK Circuit Diagram ............................................. 6
SK Circuit Board & Wiring ....................................... 7
PA Circuit Diagram ............................................. 8
PA Circuit Board & Wiring ....................................... 9
PB Circuit Diagram ............................................. 10
PB Circuit Board & Wiring ....................................... 1 I
VCO Circuit Diagram ............................................. 12
VCO Circuit Board & Wiring ....................................... 13
FA Circuit Diagram ............................................. 14
FA Circuit Board & Wiring ....................................... 15
MOD Circuit Diagram ............................................. 16
MOD Circuit Board & Wiring ....................................... 17
PGM Circuit Diagram ............................................. 18
PGM Circuit Board & Wiring ....................................... 19
DM Circuit Diagram ............................................. 20
DM Circuit Board & Wiring ....................................... 21
PL Circuit Diagram ............................................. 22
PL Circuit Board & Wiring ....................................... 23
JK1, JK2 Circuit Diagram ............................................. 24
JK1, JK2 Circuit Board & Wiring ....................................... 25
MK, BL Circuit Diagram ............................................. 26
BL Circuit Board & Wiring ....................................... 27
DC Circuit Diagram ............................................. 28
DC Circuit Board & Wiring ....................................... 29

ELECTRICAL CHECKS & ADJUSTMENTS ....................... 30

PARTS LIST ............................................... 55

Page 2

CODING GUIDE

ll Wiring Notation

:

Terminal name on the Circuit Board

TP23

4L>fll€lita Pm 112-er

/-"Circuit Board name of destination

Note: Types of wire

[El-iillwnl _ V ,
I \_Tarminal name on the destination BL Ordinary wire
' Circuit Board
I Color code of the wire BL
: -EShield wire
Symbol Description
E
E c a 7 E: Emitter _ . .
Transistor 6J4; C: Collector Capacitors --§-+ EiECtrDIyUC capacnor
C r '~ B: Base Polaritv
A : Tantalum capacitor
5 NF: Nonpolar capacitor
_ S: Source
FET G 63>) G: Gate HP
0 i 'i D: Drain Mylar, ceramic or
polystyrene capacitor
B
> on Bi Break
Diode + ->]- Swrtch T0) or T' Transfer
. c on M? Make
(Zener Diode) M
a Abbreviations of Wire Color Codes
BLACM? D: .................. BL BROWNi-f f), .................... BR RED 17h)- .................... RE
ORANGE: 5 i )- ~ UR VELLOW($./) ----------------------- ~VE GREEN: a r)
BLUEK71)' , V'BE VlOLETlAfii' .................. Vl GRAYl/MV-
WHiTE(»/ D) -WH GRASS GREEN 7 +7) ------------------ ca SKY mun / 5) --------------- -SB
PlNK(¥T€) , PK TRANSPARENTi r'vx r )-~ - ~ A -TR
Relation of Color Coding and Notes
C C 5 D D 5 E F F 3 G C 3 A A 3 B
l
| l l | l l l i i i | |
BR RE OR YE; OR BE Vi (5V WH (5G 58 PK
Hr) {771)(94)(#1)(Eril77r)[Lfi))(/\4)l~yD)(7#)l/5)(-E¥)
L09": symbols Excluswe OR NOT
(iiiiflfiflifiigfii (inverter)
Mil. YAMAHA
21D 7, Ai>w
NOT A DW V A i>¢ V . Truth Table Truth Table
A A A B Y A V
NOR D-r + . r L L L L n
a a I H L H
A A L H H
NAND BDY 5307' H H L H Li
NOR AND NAND
A A
Truth Table Truth Table Truth Table Truth Table
7 A , a v W A s v A a v A a i v
L L L L L H L L L L L h
H L H H L L H L L H L H
L H H L H L L H L L H H
H H N H H L H H n H H L